Chronic wasting disease has been discovered in the wild deer population in
Macon County, and residents are concerned about how it will affect the hunting
industry in the region. ¦ Carrie Durkee

BY Hannah Wiese, John McLaughlin

COLUMBIA — When Missouri confirmed its first case of chronic wasting
disease in a captive white-tailed buck at the Linn County Heartland Wildlife
Ranch in February 2010, state and federal officials soon agreed on the need to
kill all of the deer in an infected 800-acre pasture on the property.

Yet it took nearly a year from the time the disease was confirmed at the
commercial hunting operation for officials to move in and start killing all the
game, according to a 2011 Animal and Plant Health Inspection Service
report.

A gunner and two spotters, one using an infrared scope, aboard a Missouri
Conservation Department helicopter swept the 800-acre pasture in April 2011
looking for the final few deer but saw none. An inspection of the pasture the
following month affirmed that the captive deer were dead — 100 in all.

The 100 dead deer were buried in the infected 800-acre pasture with no
additional positives found, said Jason Sumners, deer biologist for the Missouri
Conservation Department.

Jay Brasher of Utah, who owns the Linn County ranch where the disease was
detected, told the Missourian in November that the U.S. Department of
Agriculture reimbursed him more than $100,000 for the captive deer killed on the
800 acres at his fenced hunting operation in Linn County.

“It wasn’t nearly what the animals were worth,” he said.

Captive game at the commercial hunting ranch include red deer, white-tailed
deer, Rocky Mountain elk, American bison and sheep, according to the ranch's
website.

Before depopulating the infected pasture, ranch staff killed 46
white-tailed deer and four red deer from the enclosed 800 acres to test for the
disease. The staff also killed 20 elk cows and an additional 10 red deer from
separate enclosures at the facility for testing. No positive results for chronic
wasting disease were found.

For a three-day, three-night hunt at a Heartland Wildlife Ranch, prices
range from $1,800 to kill a cow elk to upwards of $18,500 for a trophy red stag,
according to Heartland's 2011 pricing guide.

Bagging a trophy white-tailed buck can cost $15,500 or more, according to
the guide.

After depopulating the infected Linn County pasture, testing 10 miles away
at a separate commercial hunting facility owned by Brasher in Macon County found
the disease in one white-tailed deer in October, another in December and two
cases in March.

The discoveries in Macon County came as the federal government was cutting
$17 million in nationwide assistance used for compensating owners of infected
captive deer herds killed in an effort to control the disease, according to the
U.S. Department of Agriculture's 2012 budget.

The funding cut also eliminated federal assistance in monitoring for the
disease in wild and captive deer, leaving Missouri and other states on their own
in the fiscal battle to keep the disease in check.

Now that the disease has jumped into the wild population, the Missouri
Conservation Department plans to step up testing in counties around the two
ranches and is pushing new measures designed to contain the disease.

While the state quarantined the Macon County ranch and ordered it
depopulated, there's no federal money to help, Sumners said.

Without federal compensation, Brasher said in November that he had
considered not killing off deer at his Macon County facility. If he were not to
do so, the Missouri Agriculture Department would slap a permanent quarantine on
the facility designed to keep the captive deer from leaving the fenced
enclosure, according to the department.

Healthy deer, including those in the wild population, can get the disease
from nose-to-nose contact with an infected deer, contact with an infected deer's
excrement, mere contact with disease-laced soil or other contact with an
infected deer, Sumners said.

The Missouri Conservation Department's Wildlife Code calls for the fencing
of captive game such as deer to be 8 feet high and "constructed with material of
sufficient strength to prevent escape."

Matt Dunfee, coordinator for the nongovernmental Chronic Wasting Disease
Alliance, said "it is highly probable, if not a certainty" that captive deer
stick their noses through fencing to make contact with wild deer, particularly
during mating season.

Sumners said the fencing at the Linn and Macon County Heartland Wildlife
Ranches meets Missouri standards, and the fencing material is woven wire with 4
square-inches of space between the wires. He said confined deer are capable of
sticking their noses through the gaps.

In January, a Linn County landowner wrote to the Missouri Conservation
Department noting he had seen a white-tailed doe inside a Heartland Wildlife
Ranch enclosure jump and clear the 8-foot fencing, according to documents
provided by the Missouri Department of Agriculture.

In a return email, Christine Tew, spokeswoman for the Missouri Agriculture
Department, told the landowner that a depopulation of the facility was under way
and a quarantine was in place to prevent live deer from exiting the commercial
hunting operation's property without testing.

The Missouri Agriculture Department announced on May 7 that the
depopulation of the infected Macon County commercial hunting facility was
complete, with the ranch's staff handling the killing of 366 total cervids, or
any of various hoofed animals such as deer and elk, at the 3,000-acre facility
since October 2011 — when the disease was first confirmed at the property.

Ten total slaughtered cervids from the Macon County facility tested
positive for the disease, and the operation remains under quarantine. State and
federal officials will conduct a final inspection of the facility to ensure the
depopulation is finished, according to the Missouri Agriculture
Department.

Officials from the Conservation, Agriculture, and Health and Senior
Services departments plan to work with Brasher and his staff in developing a
five-year management plan, according to the department.

Linda Hickam, state veterinarian for the Missouri Agriculture Department,
could not be reached in previous attempts for an interview, and Dane Henry — a
veterinary medical officer at the Animal and Plant Health Inspection Service —
said department policy prohibited him from speaking directly with
journalists.

Dunfee said delays in depopulating all of the deer from the two ranches
could have compromised efforts in Missouri to keep the disease in check.

If Missouri had killed off deer at the commercial hunting operations right
away, the state might have been able to stop the disease from spreading into the
wild population, he said.

Billion-dollar deer

The loss in federal funds couldn't have come at a worse time for Missouri,
which is moving from detecting the disease to trying to contain it.

Soon after the federal cuts, the state's first wild white-tailed deer
tested positive for the disease within two miles of the infected Macon County
commercial hunting operation, which would have made Missouri eligible for an
increase in federal funding.

Five total diseased wild deer have been found to date, all of which were
killed within two miles of each other outside of the Macon County ranch.

Missouri would have been in the same tier of funding as Wisconsin — which
lost about $2 million to fight its outbreak, according to the Wisconsin
Department of Natural Resources.

The U.S. Department of Agriculture issued funding in three tiers:

■ Tier 1 funding, the greatest amount provided, went to states with wild
deer infected with the disease.

■Tier 2 funding went to states with neighboring states having wild
infections.

■Tier 3 funding went to states with neither wild infections nor
neighboring states with wild infections, which received no money.

The Missouri Conservation Department began testing for chronic wasting
disease in 2002 and paid for it in-house until 2006, when the federal government
pitched in the first time with $90,000.

By 2007, the U.S. Department of Agriculture had cut its share of Missouri
assistance to $75,000, and in 2010 the amount declined to $70,000, according to
the Conservation Department.

The $70,000 covered statewide testing prior to finding the disease in
Missouri, Sumners said. Now that money will have to come from elsewhere in the
Conservation Department budget.

“Seventy thousand dollars is no small amount of money,” he said. "While it
probably won’t affect chronic wasting disease testing, it could impact something
else getting done. We’re still going to do testing, absolutely.”

From where in the department the money will come has yet to be determined,
he said. “At this point, I don’t see the cut impacting how we do
business.”

The Conservation Department plans to step up its testing of hunter-killed
deer during hunting season and has established a six-county perimeter around
where the diseased wild deer were detected — outside the infected Macon County
commercial hunting facility, Sumners said.

The department will also sample random deer provided by area taxidermists
in northern Missouri, Sumners said. The samples will be mostly bucks, which are
more likely to carry the disease, he said. Last year, the department focused on
southern Missouri for random taxidermist testing.

As reported previously by the Missourian, the measures being considered
include:

■Targeted culling, or selectively shooting deer from within a site known
to be infected to slim out the population.

In May, the department approved a ban on recreational deer feeders in a six
county perimeter of the infected Macon County ranch, which includes: Adair,
Chariton, Linn, Macon, Randolph and Sullivan counties.

The department also approved removing antler-size restrictions in the
six-county area to allow for more killing of bucks, which are more likely to
carry the disease.

Within the six-county area, the department recommends that hunters not
remove whole carcasses or carcass parts, especially the head or spinal
column.

Processed and wrapped meat, meat that has had bones removed, other portions
of the deer lacking head and spinal cord parts, hides or capes, with all the
excess tissue removed, antlers, antlers attached to scull plats or sculls
lacking brain and muscle tissue, upper canine teeth, and finished taxidermy
products make the exceptions to this recommendation.

“Deer are worth $1.1 billion to Missouri,” Sumners said, and efforts to
protect them will continue.

Risky syndrome

Chronic wasting disease kills cervids — such as elk, moose and deer — and
has not yet been proven to affect livestock, house pets or humans, according to
the Missouri Agriculture, and Health and Senior Services departments.

Symptoms of the syndrome are extreme weight loss, tremors, stumbling and
excessive salivation, and deer might carry the disease without displaying any
symptoms for three or more years, according to the Missouri Conservation
Department.

The department recommends that hunters concerned about possible disease
transmission wear rubber or latex gloves when field dressing and processing
deer.

At the Linn County Heartland Wildlife Ranch, exposed carcass remains were
found at five locations during depopulation efforts, according to the Animal and
Plant Health Inspection Service report.

One location was an above-ground enclosure made of hay bales — which might
have been leaching carcass runoff into nearby private land — that shared a
fenced enclosure with captive red deer, the report stated. The other sites were
uncovered carcass pits.

"Depending on when the infection was introduced," these carcass disposal
sites might have been a source of disease exposure, according to the
report.

Dunfee said infective prions can remain in the soil for at least three
years, and every previous effort to clean an infected environment has
failed.

Brasher said he was allowed to place non-native red deer back in the
infected 800-acre enclosure and continue his hunting operation. He said in
November that the Macon County Heartland Wildlife Ranch was for sale, but that
he intended to repopulate the ranch and reopen it to hunting if it doesn't
sell.

The ranch carries a price tag of $16.5 million after the listing was
reduced by $5 million, according to Open Fences and other land broker
websites.

The lack of federal assistance crippled national surveillance for the
disease, Dunfee said. “Most states will likely reduce or stop active
surveillance" for chronic wasting disease, he said. "We can’t stop it.”

>>> Chronic wasting disease kills cervids — such as elk, moose and
deer — and has not yet been proven to affect livestock, house pets or humans,
according to the Missouri Agriculture, and Health and Senior Services
departments.

CWD HAS PROVEN to infect, cattle, cats, 4 North American rodents and a new
prion disease has been found in dogs. ...please see ;

see what CWD did with first and second passage of testing in the lab to
cattle ;

first passage ;

These findings demonstrate that when CWD is directly inoculated into the
brain of cattle, 86% of inoculated cattle develop clinical signs of the disease.

Beginning 10-12 months post inoculation (PI), all inoculates lost appetite
and weight. Five animals subsequently developed clinical signs of central
nervous system (CNS) abnormality. By 16.5 months PI, all cattle had been
euthanized because of poor prognosis. None of the animals showed microscopic
lesions of spongiform encephalopathy (SE) but the CWD agent was detected in
their CNS tissues by 2 laboratory techniques (IHC and WB). These findings
demonstrate that inoculated cattle amplify CWD agent but also develop clinical
CNS signs without manifestation of microscopic lesions of SE. This situation has
also been shown to occur following inoculation of cattle with another TSE agent,
namely, sheep scrapie.

1Institute for Neurodegenerative Diseases, University of California, San
Francisco, San Francisco, California 94143 2Department of Neurology, University
of California, San Francisco, San Francisco, California 94143 Correspondence:
stanley@ind.ucsf.edu

SNIP...

Greetings,

I believe the statement and quote below is incorrect ;

"CWD has been transmitted to cattle after intracerebral inoculation,
although the infection rate was low (4 of 13 animals [Hamir et al. 2001]). This
finding raised concerns that CWD prions might be transmitted to cattle grazing
in contaminated pastures."

Please see ;

Within 26 months post inoculation, 12 inoculated animals had lost weight,
revealed abnormal clinical signs, and were euthanatized. Laboratory tests
revealed the presence of a unique pattern of the disease agent in tissues of
these animals. These findings demonstrate that when CWD is directly inoculated
into the brain of cattle, 86% of inoculated cattle develop clinical signs of the
disease.

Thank you for your correspondence regarding the review article Stanley
Prusiner and I recently wrote for Cold Spring Harbor Perspectives. Dr. Prusiner
asked that I reply to your message due to his busy schedule. We agree that the
transmission of CWD prions to beef livestock would be a troubling development
and assessing that risk is important. In our article, we cite a peer-reviewed
publication reporting confirmed cases of laboratory transmission based on
stringent criteria. The less stringent criteria for transmission described in
the abstract you refer to lead to the discrepancy between your numbers and ours
and thus the interpretation of the transmission rate. We stand by our assessment
of the literature--namely that the transmission rate of CWD to bovines appears
relatively low, but we recognize that even a low transmission rate could have
important implications for public health and we thank you for bringing attention
to this matter.

Warm Regards, David Colby

--

David Colby, PhDAssistant ProfessorDepartment of Chemical
EngineeringUniversity of Delaware

Domestic and non-domestic cats have been shown to be susceptible to feline
spongiform encephalopathy (FSE); very likely due to consumption of bovine
spongiform encephalopathy (BSE) contaminated meat. Because domestic and
free-ranging nondomestic felids scavenge cervid carcasses, including those in
areas affected by chronic wasting disease (CWD), we evaluated the susceptibility
of domestic cats to CWD infection experimentally. Groups of n = 5 cats each were
inoculated either intracerebrally (IC) or orally (PO) with CWD-infected deer
brain homogenate.

Between 40 and 43 months two IC-inoculated cats developed slowly
progressive symptoms including weight loss, anorexia, polydipsia, patterned
motor behaviors, and ataxia”’ultimately mandating euthanasia. PrPCWD was
detected in the brains of these animals by western blot, immunohistochemistry
(IHC), and quaking-induced conversion (RT-QuIC) assays. No clinical signs of TSE
were detected in the remaining primary passage cats at 86 months pi.
Feline-adapted CWD (FelCWD) was sub-passaged into groups (n = 4 or 5) of cats by
IC, PO, and IP/SQ routes.

All 5 IC inoculated cats developed symptoms of disease 20–24 months pi
(approximately half the incubation period of primary passage). Additional
symptoms in these animals included increasing aggressiveness and hyper
responsiveness. FelCWD was demonstrated in the brains of all the affected cats
by western blot and IHC. Currently, 3 of 4 IP/SQ, and 1 of 4 PO inoculated cats
have developed abnormal behavior patterns consistent with the early stage of
feline CWD. Magnetic resonance imaging (MRI) has been performed on 11 cats (6
clinically ill, 2 asymptomatic, and 3 age-matched negative controls).
Abnormalities were detected in 4 of 6 clinically ill cats and included
multifocal signal changes consistent with inflammation, ventricular size
increases, more prominent sulci, and white matter tract cavitation.

These results demonstrate that CWD can be transmitted and adapted to the
domestic cat, and raise the potential for cervid-to-feline transmission in
nature.

========================

OR-12: Chronic wasting disease transmission and pathogenesis in cervid and
non-cervid Species

Since its recognition as a TSE in the late 1970s, chronic wasting disease
(CWD) of cervids has been distinguished by its facile spread and is now
recognized in 18 states, 2 Canadian provinces, and South Korea. The efficient
horizontal spread of CWD reflects a prion/host relationship that facilitates
efficient mucosal uptake, peripheral lymphoid amplification, and dissemination
by exploiting excretory tissues and their products, helping to establish
indirect/environmental and well as direct (e.g., salivary) transmission. Recent
studies from our group also support the likelihood of early life mother to
offspring and aerosol CWD prion transmission. Studies of cervid CWD exposure by
natural routes indicate that incubation period for detection of overt infection,
while still uncertain, may be much longer than originally thought.

Several non-cervid species can be infected by CWD experimentally (e.g.,
ferrets, voles, cats) with consequent species-specific disease phenotypes. The
species-adapted prions so generated can be transmitted by mucosal, i.e., more
natural, routes. Whether non-cervid species sympatric with deer/elk can be
infected in nature, however, remains unknown. In vitro CWD prion amplification
studies, in particular sPMCA, can foreshadow in vivo susceptibility and suggest
the importance of the PrPC rigid loop region in species barrier permissiveness.
Trans-species CWD amplification appears to broaden the host range/strain
characteristics of the resultant prions. The origins of CWD remain unknown,
however, the existence of multiple CWD prion strains/ quasi-species, the
mechanisms of prion shedding/dissemination, and the relationship between sheep
scrapie and CWD merit further investigation.

4 American rodents are susceptible to CWD to date. are those double fences
going to stop these rodents from escaping these game farms once becoming exposed
to CWD?

Chronic Wasting Disease Susceptibility of Four North American Rodents

Chad J. Johnson1*, Jay R. Schneider2, Christopher J. Johnson2, Natalie A.
Mickelsen2, Julia A. Langenberg3, Philip N. Bochsler4, Delwyn P. Keane4, Daniel
J. Barr4, and Dennis M. Heisey2 1University of Wisconsin School of Veterinary
Medicine, Department of Comparative Biosciences, 1656 Linden Drive, Madison WI
53706, USA 2US Geological Survey, National Wildlife Health Center, 6006
Schroeder Road, Madison WI 53711, USA 3Wisconsin Department of Natural
Resources, 101 South Webster Street, Madison WI 53703, USA 4Wisconsin Veterinary
Diagnostic Lab, 445 Easterday Lane, Madison WI 53706, USA *Corresponding author
email: cjohnson@svm.vetmed.wisc.edu We intracerebrally challenged four species
of native North American rodents that inhabit locations undergoing cervid
chronic wasting disease (CWD) epidemics. The species were: deer mice (Peromyscus
maniculatus), white-footed mice (P. leucopus), meadow voles (Microtus
pennsylvanicus), and red-backed voles (Myodes gapperi). The inocula were
prepared from the brains of hunter-harvested white-tailed deer from Wisconsin
that tested positive for CWD. Meadow voles proved to be most susceptible, with a
median incubation period of 272 days. Immunoblotting and immunohistochemistry
confirmed the presence of PrPd in the brains of all challenged meadow voles.
Subsequent passages in meadow voles lead to a significant reduction in
incubation period. The disease progression in red-backed voles, which are very
closely related to the European bank vole (M. glareolus) which have been
demonstrated to be sensitive to a number of TSEs, was slower than in meadow
voles with a median incubation period of 351 days. We sequenced the meadow vole
and red-backed vole Prnp genes and found three amino acid (AA) differences
outside of the signal and GPI anchor sequences. Of these differences (T56-,
G90S, S170N; read-backed vole:meadow vole), S170N is particularly intriguing due
its postulated involvement in "rigid loop" structure and CWD susceptibility.
Deer mice did not exhibit disease signs until nearly 1.5 years post-inoculation,
but appear to be exhibiting a high degree of disease penetrance. White-footed
mice have an even longer incubation period but are also showing high penetrance.
Second passage experiments show significant shortening of incubation periods.
Meadow voles in particular appear to be interesting lab models for CWD. These
rodents scavenge carrion, and are an important food source for many predator
species. Furthermore, these rodents enter human and domestic livestock food
chains by accidental inclusion in grain and forage. Further investigation of
these species as potential hosts, bridge species, and reservoirs of CWD is
required.

It was also hypothesized that BSE might have originated from an
unrecognized sporadic or genetic case of bovine prion disease incorporated into
cattle feed or even cattle feed contaminated with prion-infected human remains.1
However, strong support for a genetic origin of BSE has recently been
demonstrated in an H-type BSE case exhibiting the novel mutation E211K.2
Furthermore, a specific prion protein strain causing BSE in cattle is believed
to be the etiological agent responsible for the novel human prion disease,
variant Creutzfeldt-Jakob disease (vCJD).3 Cases of vCJD have been identified in
a number countries, including France, Italy, Ireland, the Netherlands, Canada,
Japan, US and the UK with the largest number of cases. Naturally occurring
feline spongiform encephalopathy of domestic cats4 and spongiform
encephalopathies of a number of zoo animals so-called exotic ungulate
encephalopathies5,6 are also recognized as animal prion diseases, and are
thought to have resulted from the same BSE-contaminated food given to cattle and
humans, although and at least in some of these cases, a sporadic and/or genetic
etiology cannot be ruled out. The canine species seems to display resistance to
prion disease and no single case has so far been reported.7,8 Here, we describe
a case of a 9 week old male Rottweiler puppy presenting neurological deficits;
and histological examination revealed spongiform vacuolation characteristic of
those associated with prion diseases.9 Initial biochemical studies using
anti-PrP antibodies revealed the presence of partially proteinase K-resistant
fragment by western blotting. Furthermore, immunohistochemistry revealed
spongiform degeneration consistent with those found in prion disease and
displayed staining for PrPSc in the cortex.

Of major importance, PrPSc isolated from the Rottweiler was able to cross
the species barrier transmitted to hamster in vitro with PMCA and in vivo (one
hamster out of 5). Futhermore, second in vivo passage to hamsters, led to 100%
attack rate (n = 4) and animals displayed untypical lesional profile and shorter
incubation period.

In this study, we show that the canine species might be sensitive to prion
disease and that PrPSc isolated from a dog can be transmitted to dogs and
hamsters in vitro using PMCA and in vivo to hamsters. If our preliminary results
are confirmed, the proposal will have a major impact on animal and public health
and would certainly lead to implementing new control measures for ‘canine
spongiform encephalopathy’ (CSE).

Chronic wasting disease (CWD) is the only known transmissible spongiform
encephalopathy affecting free-ranging wildlife. Experimental and epidemiological
data indicate that CWD can be transmitted horizontally and via blood and saliva,
although the exact mode of natural transmission remains unknown. Substantial
evidence suggests that prions can persist in the environment, implicating it as
a potential prion reservoir and transmission vehicle. CWD- positive animals can
contribute to environmental prion load via biological materials including
saliva, blood, urine and feces, shedding several times their body weight in
possibly infectious excreta in their lifetime, as well as through decomposing
carcasses. Sensitivity limitations of conventional assays hamper evaluation of
environmental prion loads in water. Here we show the ability of serial protein
misfolding cyclic amplification (sPMCA) to amplify minute amounts of CWD prions
in spiked water samples at a 1:1 x106 , and protease-resistant prions in
environmental and municipal-processing water samples from a CWD endemic area.
Detection of CWD prions correlated with increased total organic carbon in water
runoff from melting winter snowpack. These data suggest prolonged persistence
and accumulation of prions in the environment that may promote CWD transmission.

snip...

The data presented here demonstrate that sPMCA can detect low levels of
PrPCWD in the environment, corroborate previous biological and experimental data
suggesting long term persistence of prions in the environment2,3 and imply that
PrPCWD accumulation over time may contribute to transmission of CWD in areas
where it has been endemic for decades. This work demonstrates the utility of
sPMCA to evaluate other environmental water sources for PrPCWD, including
smaller bodies of water such as vernal pools and wallows, where large numbers of
cervids congregate and into which prions from infected animals may be shed and
concentrated to infectious levels.

CWD has been identified in free-ranging cervids in 15 US states and 2
Canadian provinces and in ≈ 100 captive herds in 15 states and provinces and in
South Korea (Figure 1, panel B).

SNIP...

Long-term effects of CWD on cervid populations and ecosystems remain
unclear as the disease continues to spread and prevalence increases. In captive
herds, CWD might persist at high levels and lead to complete herd destruction in
the absence of human culling. Epidemiologic modeling suggests the disease could
have severe effects on free-ranging deer populations, depending on hunting
policies and environmental persistence (8,9). CWD has been associated with large
decreases in free-ranging mule deer populations in an area of high CWD
prevalence (Boulder, Colorado, USA) (5).

The transmission of bovine spongiform encephalopathy (BSE) to human beings
and the spread of chronic wasting disease (CWD) among cervids have prompted
concerns about zoonotic transmission of prion diseases. Travel to the United
Kingdom and other European countries, hunting for deer or elk, and venison
consumption could result in the exposure of US residents to the agents that
cause BSE and CWD. The Foodborne Diseases Active Surveillance Network 2006-2007
population survey was used to assess the prevalence of these behaviors among
residents of 10 catchment areas across the United States. Of 17,372 survey
respondents, 19.4% reported travel to the United Kingdom since 1980, and 29.5%
reported travel to any of the nine European countries considered to be
BSE-endemic since 1980. The proportion of respondents who had ever hunted deer
or elk was 18.5%, and 1.2% had hunted deer or elk in a CWD–endemic area. More
than two thirds (67.4%) reported having ever eaten deer or elk meat. Respondents
who traveled spent more time in the United Kingdom (median 14 days) than in any
other BSE-endemic country. Of the 11,635 respondents who had consumed venison,
59.8% ate venison at most one to two times during their year of highest
consumption, and 88.6% had obtained all of their meat from the wild. The survey
results were useful in determining the prevalence and frequency of behaviors
that could be important factors for foodborne prion transmission.

"These findings indicate that a high percentage of the United States
population engages in hunting and/or venison consumption. If CWD continues to
spread to more areas across the country, a substantial number of people could
potentially be exposed to the infectious agent."

The foodborne transmission of bovine spongiform encephalopathy to humans,
resulting in variant Creutzfeldt-Jakob disease, indicates that humans can be
susceptible to animal prion diseases. However, it is not known whether foodborne
exposure to the agent causing chronic wasting disease (CWD) in cervids can cause
human disease. The United States Foodborne Diseases Active Surveillance Network
(FoodNet) conducts surveillance for foodborne diseases through an extensive
survey administered to respondents in selected states. To describe the frequency
of deer and elk hunting and venison consumption, five questions were included in
the 2006-2007 FoodNet survey. This survey included 17,372 respondents in ten
states: California, Colorado, Connecticut, Georgia, Maryland, Minnesota, New
Mexico, New York, Oregon, and Tennessee. Of these respondents, 3,220 (18.5%)
reported ever hunting deer or elk, with 217 (1.3%) reporting hunting in a
CWD-endemic area (northeastern Colorado, southeastern Wyoming, and southwestern
Nebraska). Of the 217 CWD-endemic area hunters, 74 (34.1%) were residents of
Colorado. Respondents reporting hunting were significantly more likely to be
male than female (prevalence ratio: 3.3, 95% confidence interval: 3.1-3.6) and,
in general, older respondents were significantly more likely to report hunting
than younger respondents. Venison consumption was reported by more than half
(67.4%) of the study population, and most venison consumers (94.1%) reported
that at least half of their venison came from the wild. However, more than half
(59.1%) of the consumers reported eating venison only one to five times in their
life or only once or twice a year. These findings indicate that a high
percentage of the United States population engages in hunting and/or venison
consumption. If CWD continues to spread to more areas across the country, a
substantial number of people could potentially be exposed to the infectious
agent.

In the Archives of Neurology you quoted (the abstract of which was attached
to your email), we did not say CWD in humans will present like variant CJD.

That assumption would be wrong. I encourage you to read the whole article
and call me if you have questions or need more clarification (phone:
404-639-3091). Also, we do not claim that "no-one has ever been infected with
prion disease from eating venison." Our conclusion stating that we found no
strong evidence of CWD transmission to humans in the article you quoted or in
any other forum is limited to the patients we investigated.

CDC assesses potential human exposure to prion diseases Study results
reported in the Journal of the American Dietetic Association Philadelphia, PA,
May 23, 2011 – Researchers from the Centers for Disease Control and Prevention
(CDC) have examined the potential for human exposure to prion diseases, looking
at hunting, venison consumption, and travel to areas in which prion diseases
have been reported in animals. Three prion diseases in particular – bovine
spongiform encephalopathy (BSE or "Mad Cow Disease"), variant Creutzfeldt-Jakob
disease (vCJD), and chronic wasting disease (CWD) – were specified in the
investigation. The results of this investigation are published in the June issue
of the Journal of the American Dietetic Association.

"While prion diseases are rare, they are generally fatal for anyone who
becomes infected. More than anything else, the results of this study support the
need for continued surveillance of prion diseases," commented lead investigator
Joseph Y. Abrams, MPH, National Center for Emerging and Zoonotic Infectious
Diseases, CDC, Atlanta."But it's also important that people know the facts about
these diseases, especially since this study shows that a good number of people
have participated in activities that may expose them to infection-causing
agents."

Although rare, human prion diseases such as CJD may be related to BSE.
Prion (proteinaceous infectious particles) diseases are a group of rare brain
diseases that affect humans and animals. When a person gets a prion disease,
brain function is impaired. This causes memory and personality changes,
dementia, and problems with movement. All of these worsen over time. These
diseases are invariably fatal. Since these diseases may take years to manifest,
knowing the extent of human exposure to possible prion diseases could become
important in the event of an outbreak.

CDC investigators evaluated the results of the 2006-2007 population survey
conducted by the Foodborne Diseases Active Surveillance Network (FoodNet). This
survey collects information on food consumption practices, health outcomes, and
demographic characteristics of residents of the participating Emerging
Infections Program sites. The survey was conducted in Connecticut, Georgia,
Maryland, Minnesota, New Mexico, Oregon, and Tennessee, as well as five counties
in the San Francisco Bay area, seven counties in the Greater Denver area, and 34
counties in western and northeastern New York.

Survey participants were asked about behaviors that could be associated
with exposure to the agents causing BSE and CWD, including travel to the nine
countries considered to be BSE-endemic (United Kingdom, Republic of Ireland,
France, Portugal, Switzerland, Italy, the Netherlands, Germany, Spain) and the
cumulative length of stay in each of those countries. Respondents were asked if
they ever had hunted for deer or elk, and if that hunting had taken place in
areas considered to be CWD-endemic (northeastern Colorado, southeastern Wyoming
or southwestern Nebraska). They were also asked if they had ever consumed
venison, the frequency of consumption, and whether the meat came from the wild.

The proportion of survey respondents who reported travel to at least one of
the nine BSE endemic countries since 1980 was 29.5%. Travel to the United
Kingdom was reported by 19.4% of respondents, higher than to any other
BSE-endemic country. Among those who traveled, the median duration of travel to
the United Kingdom (14 days) was longer than that of any other BSE-endemic
country. Travelers to the UK were more likely to have spent at least 30 days in
the country (24.9%) compared to travelers to any other BSE endemic country. The
prevalence and extent of travel to the UK indicate that health concerns in the
UK may also become issues for US residents.

The proportion of survey respondents reporting having hunted for deer or
elk was 18.5% and 1.2% reported having hunted for deer or elk in CWD-endemic
areas. Venison consumption was reported by 67.4% of FoodNet respondents, and
88.6% of those reporting venison consumption had obtained all of their meat from
the wild. These findings reinforce the importance of CWD surveillance and
control programs for wild deer and elk to reduce human exposure to the CWD
agent. Hunters in CWD-endemic areas are advised to take simple precautions such
as: avoiding consuming meat from sickly deer or elk, avoiding consuming brain or
spinal cord tissues, minimizing the handling of brain and spinal cord tissues,
and wearing gloves when field-dressing carcasses.

According to Abrams, "The 2006-2007 FoodNet population survey provides
useful information should foodborne prion infection become an increasing public
health concern in the future. The data presented describe the prevalence of
important behaviors and their associations with demographic characteristics.
Surveillance of BSE, CWD, and human prion diseases are critical aspects of
addressing the burden of these diseases in animal populations and how that may
relate to human health."

Thank you for your recent letter concerning the publication of the third
annual report from the CJD Surveillance Unit. I am sorry that you are
dissatisfied with the way in which this report was published.

The Surveillance Unit is a completely independant outside body and the
Department of Health is committed to publishing their reports as soon as they
become available. In the circumstances it is not the practice to circulate the
report for comment since the findings of the report would not be amended. In
future we can ensure that the British Deer Farmers Association receives a copy
of the report in advance of publication.

The Chief Medical Officer has undertaken to keep the public fully informed
of the results of any research in respect of CJD. This report was entirely the
work of the unit and was produced completely independantly of the the
Department.

The statistical results reqarding the consumption of venison was put into
perspective in the body of the report and was not mentioned at all in the press
release. Media attention regarding this report was low key but gave a realistic
presentation of the statistical findings of the Unit. This approach to
publication was successful in that consumption of venison was highlighted only
once by the media ie. in the News at one television proqramme.

I believe that a further statement about the report, or indeed statistical
links between CJD and consumption of venison, would increase, and quite possibly
give damaging credence, to the whole issue. From the low key media reports of
which I am aware it seems unlikely that venison consumption will suffer
adversely, if at all.

Interspecies transmission studies afford the opportunity to better
understand the potential host range and origins of prion diseases. Previous
experiments demonstrated that white-tailed deer are susceptible to sheep-derived
scrapie by intracranial inoculation. The purpose of this study was to determine
susceptibility of white-tailed deer to scrapie after a natural route of
exposure. Deer (n=5) were inoculated by concurrent oral (30 ml) and intranasal
(1 ml) instillation of a 10% (wt/vol) brain homogenate derived from a sheep
clinically affected with scrapie. Non-inoculated deer were maintained as
negative controls. All deer were observed daily for clinical signs. Deer were
euthanized and necropsied when neurologic disease was evident, and tissues were
examined for abnormal prion protein (PrPSc) by immunohistochemistry (IHC) and
western blot (WB). One animal was euthanized 15 months post-inoculation (MPI)
due to an injury. At that time, examination of obex and lymphoid tissues by IHC
was positive, but WB of obex and colliculus were negative. Remaining deer
developed clinical signs of wasting and mental depression and were necropsied
from 28 to 33 MPI. Tissues from these deer were positive for scrapie by IHC and
WB. Tissues with PrPSc immunoreactivity included brain, tonsil, retropharyngeal
and mesenteric lymph nodes, hemal node, Peyer’s patches, and spleen. This work
demonstrates for the first time that white-tailed deer are susceptible to sheep
scrapie by potential natural routes of inoculation. In-depth analysis of tissues
will be done to determine similarities between scrapie in deer after
intracranial and oral/intranasal inoculation and chronic wasting disease
resulting from similar routes of inoculation.

*** Spraker suggested an interesting explanation for the occurrence of CWD.
The deer pens at the Foot Hills Campus were built some 30-40 years ago by a Dr.
Bob Davis. At or abut that time, allegedly, some scrapie work was conducted at
this site. When deer were introduced to the pens they occupied ground that had
previously been occupied by sheep.

(PLEASE NOTE SOME OF THESE OLD UK GOVERNMENT FILE URLS ARE SLOW TO OPEN,
AND SOMETIMES YOU MAY HAVE TO CLICK ON MULTIPLE TIMES, PLEASE BE PATIENT, ANY
PROBLEMS PLEASE WRITE ME PRIVATELY, AND I WILL TRY AND FIX OR SEND YOU OLD PDF
FILE...TSS)

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About Me

My mother was murdered by what I call corporate and political homicide i.e. FOR PROFIT! she died from a rare phenotype of CJD i.e. the Heidenhain Variant of Creutzfeldt Jakob Disease i.e. sporadic, simply meaning from unknown route and source. I have simply been trying to validate her death DOD 12/14/97 with the truth. There is a route, and there is a source. There are many here in the USA. WE must make CJD and all human TSE, of all age groups 'reportable' Nationally and Internationally, with a written CJD questionnaire asking real questions pertaining to route and source of this agent. Friendly fire has the potential to play a huge role in the continued transmission of this agent via the medical, dental, and surgical arena. We must not flounder any longer. ...TSS